1. Field of the Invention
The present invention is related to coaxial conductors and, more particularly, to processes of integrating coaxial conductors onto integrated circuit chips.
2. Background Description
Coaxial cables are well known. Miniature coaxial cables are also well known. Coaxial cables are widely used for low loss data transmission. Signals transmitted on coaxial cables are shielded from exterior noise that might otherwise interfere with signals on an unshielded line.
To reduce signal loss, signals transmitted on coaxial cable require termination for impedance matching. Typical impedance matching termination on an integrated circuit (IC) chip is a resistor tied at one end to a supply.
Very few IC processes include coaxial signal distribution conductors because of the difficulty in fabricating coaxial structures in IC processes. Further, prior art coaxial conductors have irregularities in spacing between the core conductor and the outer shield conductor. These irregularities lead to nonuniform characteristic impedance along the conductor. The nonuniformity in the characteristic impedance introduces noise from reflections and attenuations into signals on the core conductor.
Thus there is a need for coaxial conductors in ICs that have uniform spacing between the core conductor and the outer shield conductor.